Stihl Saw

[sotal]

I picked up a cheap stihl saw the other day from an old chap who was having trouble starting it.

I had a go at starting it as per the instructions and got it running but once running it was electricuting me through the frame and it cut out if you let off the revs.

I've had a quick check over it and given it a cosmetic clean and found the HT lead was worn through and arcing to the casing, and the stop cable is damaged.

I insulated the HT lead and repaired the stop cable and that cured the electricuting bit but didn't change how it ran.

The engine has three adjustments, High Speed, Low Speed and Idle Speed. I tried adjusting the idle speed but it appeared to make no difference.

I then had a search on the internet and found a page which says to adjust the H and L screws all the way in then undo them 1 full turn - this will then give 'safe' settings.

The H was approx 1 turn anyway so I've barely moved that one, but the L took nearly 3 turns to turn in then I backed it out one turn.

I then started it up, which started 1st pull much easier than before and it ran at idle, the only problem now is that it doesn't rev! and it smokes a bit of blue smoke at idle.

Anyone else got one of these? Or anyone able to explain to me how to set it up!?

Cheers

[outdoor_ian]

What sort of saw is it? Chain saw, stone saw ?????

Clean out / change the air filter first and put a new plug in it.

[sotal]

Sorry it's a Stihl TS 350 Saw for Stone or Steel etc.

The Air Filter looked a bit grubby so I've removed that for now - so am running without filter if that makes a difference? Hasn't affected the running.

Plug looks good the old chap said he had replaced it recently in attempt to help him start it.

I've had a play with the H and L screws (undid L screw quarter of a turn etc) and am now back at the beginning - ie will start and run but won't idle. So I put the screw back to the 'safe' position and it's exactly the same - won't idle!

I think my next thing is to chuck out the old fuel and put new fuel in making sure the mix is correct. The current petrol looks quite red

[mickeyw]

Might also be worth squirting some carb cleaner through. If it has had old petrol in that has evaporated there may be residue blocking certain parts of the carb.

[outdoor_ian]

Ditch the old petrol and get a sachet of stihl one shot from a hire shop. This will be red so the fuel that is in it already does have 2 stroke oil in it but the age is unknown and so is the mixture.

Follow the instructions on the sachet for mixing.

[Briarston]

In addition to the advice already given, be accurate with the fuel/oil mix. Too much oil will cause bad running, too little will cause damage. Although often called "self mixing two stroke oil" always give the mixing vessel a good shaking -a proper graduated mixing bottle is available from garden machinery suppliers - and shake the machine if it's been unused for a day or two. If the machine is to be out of use for a longish period, it's usually recommended that the tank be emptied, the the m/c started and run dry.

[Les Henson]

I'm familiar with tuning chainsaws (Stihl, Husqvarna, etc). All petrol-engines machines are generally supplied from the factory to run rich - this prevents seizure of the engine if you use it hard for the first time from new, and also to over-lubricate the engine for a while. Chainsaws have to be tuned once a few tankfulls of fuel have been used and the engine is run in. Low (L) is for revs from tickover to f1/2 - 3/4 throttle, and high (H) is to the top of the revs. Setting the idle only sets the tickover, and it's the two other jets you need to concentrate on initially. Start the engine and pull the throttle all the way, then slowly screw the 'H' in, and as you do so, the engine speed will increase until it reaches the 'tone', which is a high-pitched scream. Undo the screw a very small amount to be on the safe side, then reduce the throttle to half way until the engine revs are smooth and moderately high. The engine should then run smoothly, but not necessarily tick over. Switch the engine off. If the idle screw is a jet, then screw it all the way in, then out 2-turns, and start the engine and adjust as necessary until it ticks over slightly erratically, but doesn't stall (the blade may twitch a bit on tickover). If the idle screw bears directly on an arm on the carb, then undo it until the end no longer bears on the arm and then do it up until the arm moves a couple of mm. Start the engine and adjust the tickover as previously described - undo to decrease tickover, do it up to increase the tickover.

Les.

[sotal]

Thanks for the advice, I will empty the tank out, and fill with fresh, I was going to just fill a 5 litre container up with unleaded from the pump, add 100ml of two stroke oil and shake in the petrol container - is that OK?

[Les Henson]

You need to use low ash oil and the correct amount (25/1 I think). Too much oil and the plug won't last very long and the engine will smoke.

Les.

[Night Train]

This is all useful stuff. I'm glad it has been posted. I will give my chainsaw a good service and should be able to set up from this I think.

I found that there was no effective air filter and the carb looks like an old butcher's shop floor.

[Les Henson]

You can strip and clean the carb - they are very basic. Just make a note of the position and orientation of the various gaskets - some of them are also one-way valves, so put it back together the way it came apart. Most disc cutters/chainsaws have a cleanable air filter. Carb overhaul kits are available for the more popular makes for only a few quid.

Les.

[sotal]

Thanks for the info, the manual states to use oil that's certified as TC whatever that means, and to use 50:1 mix. The carb looks easy to get to so if I can't get it running properly I will strip and clean that but at the moment I wanted to leave it together as much as possible!

The Air Filters are washable and I have done this but the inner filter looks knackered to be honest, it's a sort of steel mesh covered in a sponge type stuff. The steel mesh has rusted and swelled across the holes

Just realised I missed your first post Les, I think I posted at the same sort of time - looks very useful info and makes more sense to me than anything else I've read! Other bits I've read talked about how they made it richer/leaner and confused me! The idle on this (if I have the right bit) appears to be a rubber tube with a screw in the end.

[Les Henson]

You will also have a filter in the tank most likely. There's a pipe inside the tank with a weighted filter on the end of it (this is to ensure that the pick up is always in the fuel - regardless of the angle of the saw). Quite a fiddly thing to change, but it gets clogged with any dust or grit that gets inside the tank.

The rubber tube may well be just a guide for the screwdriver to locate on the idle screw correctly. My Huskys have the same arrangement. It's likely that the idle screw bears on an arm on the carb itself in that case.

Les.

[outdoor_ian]

Stone saws usually have a foam/sponge outer filter which can be shaken/blown clean with a I think if memory serves me rightly in your case a round cylinder type filter inside (like a very small 300tdi defender filter) that. You can bash the metal filter and most of the dust will drop out however they are not that exspensive to replace just make sure the foam/sponge outer/pre filter is a tight fit.

Chainsaws do not have a filter as above its is a plastic gauze which can be split in half and blown backwards using compressed air. Just make sure that when you remove the plastic filter you cover the carb inlet to prevent and nasty's getting inside.

Keep a chainsaw sharpe and the chip size will remain a reasonable size that impeads the filter less its mostly a dull chain that produces a slow cut and very fine chips that are almost powder which being lighter in weight get sucked up into the filter meaning more cleaning or a very poor running saw.

[dirkthe1]

Not alot to add to what everyone else has said, cept that if you have a decent plant (or arboricultural) supplies place nearby usually its cheaper to get a smallish service and tuning done by then then it is yourself.

One thing thats worth checking is that the carb screws still have springs on that work, otherwise they will move under vibration and then you will spend a day re tuning them every half hour untill you realise.

[sotal]

You will also have a filter in the tank most likely. There's a pipe inside the tank with a weighted filter on the end of it (this is to ensure that the pick up is always in the fuel - regardless of the angle of the saw). Quite a fiddly thing to change, but it gets clogged with any dust or grit that gets inside the tank.

The rubber tube may well be just a guide for the screwdriver to locate on the idle screw correctly. My Huskys have the same arrangement. It's likely that the idle screw bears on an arm on the carb itself in that case.

Les.

There is a filter in the tank but you don't seem to be able to remove it without removing the carb.

The rubber tube has the adjustmemt screw at the end, it just seems to screw into the tube, the tube isn't a guide. I was only presuming it was idle speed might have it completley wrong!

[pitmole]

Hi, I was a stihl mech for years, just to add to les's advice, if you adjust the carb like he says, then always go back and re-check

the wot settings after you have played with the low speed settings, low mixture screw will have an effect on high speed but not the other way round.

Also, that model of cutter was very prone to wear on the induction side of the cylinder due to fine stone powder ingress, this will upset the primary compression

and make it hard to start/tickover. have fun!!

[baba350_0]

check crank bearings for play and roughness these are prone to wear and this affects oil seals and compression

[sotal]

I've not done much since,

I've not had chance to get new fuel, but needed to use the saw today, Started up on about the 4th pull and carried on running, knocked the choke off and used the tool for the job I needed it for which was a few minutes running, seemed have plenty of torque and was a pleasure to use compared the the big grinder.

When I finished I released the throttle, and it stil didn't idle - it just cut out.

I did however notice that it sprayed black liquid out of the exhaust whilst running, looks like really dirty oil but cleans off fairly easily, I realise that's not normal is it from running too rich etc? It smells a bit whilst running but only like I'd expect a 2 stroke to smell, it doesn't really smoke much at all.

I can live with the black spray if needs be but don't want to be damaging it further! Any thoughts?

Thanks

[Les Henson]

Assuming that you've gpt the right fuel/2-stroke oil mixture right, then it must be unburned fuel (no water or engine oil). Run the engine for a while - 20-minutes or so above tickover, then look at the spark plug - it should be dark grey. The induction is very simple on this engine.

Les.

[Blanco]

Just to add to the sum of the above, most of these machines run Walbro carbs, search the www for Walbro and there is masses of material which helped me sort out my strimmer, just takes a little time to get into the 'zone'!! sounds like a bargain by the way....

[sotal]

Thanks for the replies, I carried on using the saw as it didn't have a lot of fuel left in. I let it run dry, then started it up again and it cut straight out.

I then managed to remember to get some fuel today and mixed in the exact amount of two stroke oil. With the correct mix it only has a light hint of red to the fuel, wheras the fuel in the saw before was much darker red.

The only bad thing is it now won't start with the proper mix in! I'm hoping it's just down to retuning it now

[sotal]

Turned out to be that the stop cable had rubbed through and was earthing stopping it from starting.

Correct fuel mix seems to have stopped the smoke, not sure about the black liquid yet as that only happened when it had been runing a while.

Still won't idle though

[sotal]

I've managed to get by for the last couple of weeks doing the occasional cut with the saw, but I now have a fair few to do at once and the damn things worse than ever!

Today it would start up then die shortly after - it felt to me like fuel starvation. After it died I had to use choke to get it to start again. If I tried straight after then it would only run for a few seconds - the longer I left it the longer it would run for (up to about 20 seconds)

I stripped down the carb to have a look to see if I could see anything. The filter in the tank was clean, but the rubber pipes feel a little old. The plastic part where the fuel pipe connects to the carb was a little gummed up but still flowing (it turned out to be bits of cork gasket)

I took everything apart that I could find and all looked fine and clean so I reassembled.

Now it doesn't start at all!

The spark is good so it must be down to fuel not getting through.

Any ideas?

I've also got a few questions:

When stripping down I took the H and L jets out. One is very pointy the other is blunt at the end - is that normal or has one broken at the end?

The idle adjustment - is that literally just the screw which moves the throttle further on?

There was a brass screw further in which seems to be in all the way - this has 14 on the top - when wound out it has some kind of hole through it - any idea what this is?

Is it normal for the blade to spin when pulling the pull start? It seems to spin all the time.

The rubber tube I mentioned before with the screw on top just goes to the tank - any idea what that is? It just connects to the top of the tank - removing it made no difference.

It was running better before with too much oil in, but smoked and spat black out of the exhaust. Now with the correct fuel it runs better in that it doesn't smoke at all and doesn't spit, but runs worse in that it keeps cutting out.

Thanks for the help

[ProteuS]

Just out of interest, does your machine have a decompressor button for startup? I've recently bought a TS410, and it's been a fantastic stonesaw so far. We also have a few stihl chainsaws and find them to be much better at starting than the husky xp we had beforehand.

As has been mentioned with fuel it can make a fair difference. I have always used the stihl 2 stroke oil with the little pot in the top that you fill up. and have had good results with it. Some builders we've had in recently swear by the makita dolmar one shot pots on their stonesaws. The stihl manuals usually reccomend 50:1 with their own two stroke oil, and 25:1 with other two stroke oils.

If you've got good spark, new fuel, and a clean carb I don't see why you shouldn't be able to get it to run up in some way, shape or form. Perhaps something like the float in the carb has got stuck.

or finally, it isn't something silly like the cut out switch having shorted or developed a fault?